Radial partitioned countercurrent air blowing bromine extraction tower system and process

Abstract

The present application provides a kind of radial partition countercurrent air blowing bromine extraction tower system and process, the system of the present application is by being provided at least one vertical concentric ring-shaped partition in tower body, and the cavity of tower is physically divided into multiple independent ring reaction zone;Matched multi-ring independent liquid distributor, can be adjusted spray density by zone;While using main auxiliary collaborative gas distribution system, main gas inlet is arranged in the center of tower bottom, and adjustable auxiliary gas inlet is arranged in lateral wall ring area, and actively disturbs unfavorable flow pattern.Combined with intelligent collaborative control, realize the dynamic optimization of each ring area gas-liquid flow field.The present application effectively improves the efficiency of bromine blowing, inhibits channeling and wall flow, reduces energy consumption, is suitable for large-scale bromine production, can also be popularized to other gas-liquid countercurrent mass transfer process, solves the technical problems such as uneven gas-liquid distribution, low mass transfer efficiency and significant amplification effect in large-diameter packed tower.

Description

Technical Field

[0001] This invention relates to the field of bromine extraction technology, and more specifically, to a radially partitioned countercurrent air blowing bromine extraction tower system and process. Background Technology

[0002] Bromine, as an important basic chemical raw material, is widely used in flame retardants, pharmaceuticals, pesticides, photosensitive materials, and oilfield drilling fluids. Currently, industrial bromine extraction mainly occurs from salt lake brine, underground brine, or seawater, primarily through the air blowing method, with the air blowing tower as its core equipment. This process generally includes three key steps: acidification oxidation, air blowing, and absorption. The mass transfer efficiency of the blowing tower directly determines the bromine recovery rate and energy consumption level of the entire bromine extraction process.

[0003] Traditional air blowing towers typically employ a single-cavity cylindrical structure, filled with either regular or random packing. Liquid is sprayed uniformly from the top, while air is blown in through the bottom sidewall, creating a counter-current contact. To improve the uniformity of gas-liquid distribution, current designs usually incorporate a liquid distributor at the top and a gas distribution plate at the bottom, employing high specific surface area packing to enhance mass transfer. In small-diameter towers, these measures can ensure good operational performance to a certain extent.

[0004] However, as bromine resource development moves towards large-scale and intensive operations, industrial bromine extraction plants are becoming increasingly larger, with significantly increased tower diameters. Against this backdrop, the traditional single-chamber structure suffers from the following shortcomings: On the one hand, influenced by the buoyancy of the gas, the rising airflow tends to converge towards the central region in large-diameter towers, forming a high-speed channel flow zone. On the other hand, influenced by gravity and the adhesion effect of the tower wall, the liquid tends to flow down the tower wall, forming a wall flow zone. The combination of these two factors leads to an imbalance in the gas-liquid distribution within the tower—the gas velocity in the central region is too high while the liquid volume is insufficient, causing dry blowing of the packing and low mass transfer efficiency; the liquid film in the edge region is too thick and the gas velocity is too low, which easily induces flooding; while the middle ring becomes a dead zone due to insufficient gas-liquid supply, resulting in a significant decrease in overall mass transfer efficiency.

[0005] To address the aforementioned issues, existing technologies primarily rely on optimizing the liquid distributor structure or adjusting the packing arrangement. However, these localized improvements are only applicable to small-diameter towers. As the tower diameter increases, the hydrodynamic behavior exhibits highly nonlinear characteristics, making it difficult to achieve globally uniform distribution through localized optimization.

[0006] Furthermore, the liquid and gas distribution systems of traditional blowdown towers are fixed structures that cannot be dynamically adjusted. When the feed concentration, temperature, flow rate, or environmental conditions change, the original gas-liquid distribution is disrupted, but there is a lack of real-time compensation mechanisms. This leads to flooding or dry zones in local areas, causing drastic fluctuations in overall tower pressure drop, poor operational stability, and even requiring frequent shutdowns for adjustments, thus affecting continuous production.

[0007] Existing control systems generally lack the ability to sense and actively intervene in the local flow field state within the tower. To compensate for insufficient mass transfer efficiency, methods such as increasing fan power and airflow are often adopted, attempting to improve the distribution by enhancing airflow disturbance. This approach not only results in persistently high power consumption per unit of bromine production but also significantly increases the tail gas treatment load; at the same time, due to the low bromine recovery rate, a large amount of bromine remains in the waste liquid, causing both resource waste and potential environmental pollution risks.

[0008] In summary, to address the urgent need for efficient, stable, and low-consumption operation in large-scale bromine extraction plants, it is necessary to overcome the inherent limitations of traditional single-cavity blow-out towers in terms of gas-liquid distribution, dynamic adaptability, and intelligent control. Therefore, a novel radially partitioned counter-current air-blowing bromine extraction tower system and its supporting processes are proposed, aiming to fundamentally solve key technical challenges such as uneven gas-liquid distribution within large-diameter towers, significant scale-up effects, and insufficient operational flexibility. Summary of the Invention

[0009] The purpose of this invention is to solve the problems raised in the background art. To this end, this invention provides the following technical solution: a radially partitioned counter-current air-blowing bromine extraction tower system, comprising a tower body, a packing layer, a liquid inlet, a gas inlet, and a liquid distributor, wherein the system integrates the following three inseparable structural features: (a) At least one vertically arranged concentric annular baffle physically divides the cross-section of the tower body into two or more concentric annular reaction zones, the baffle extending from the top of the tower to above the bottom of the packing layer, forcing the gas and liquid phases to flow independently in each annular zone; (b) A multi-ring independent liquid distributor, which includes independent liquid inlet branches corresponding to each annular reaction zone, each branch being equipped with an independently adjustable flow control valve and a distribution nozzle for classifying and adjusting the spray density of each annular zone. (c) A main-auxiliary coordinated gas distribution system, including a main gas inlet located at the center of the bottom of the tower, and at least one auxiliary gas inlet located on the side wall of the tower body corresponding to a certain annular reaction zone. The airflow direction of the auxiliary gas inlet is adjustable, and gas can be injected in a tangential, oblique or radial manner to form a three-dimensional optimized flow field in coordination with the liquid distribution.

[0010] As a preferred embodiment of the present invention, the number of concentric annular partitions is 1 to 3, dividing the tower body into 2 to 4 annular reaction zones.

[0011] As a preferred technical solution of the present invention, the fillers in each annular reaction zone have the same specific surface area, or the specific surface area increases appropriately from the inner ring to the outer ring to form a gradient filler configuration to match the mass transfer requirements of different regions.

[0012] As a preferred embodiment of the present invention, the number of auxiliary air inlets is not less than the number of annular reaction zones minus one, and at least one auxiliary air inlet is disposed on the sidewall of the outermost annular zone to actively disturb the wall liquid film and suppress wall flow.

[0013] As a preferred technical solution of the present invention, both the main air inlet and the auxiliary air inlet are connected to independent gas flow regulating devices, so that the flow ratio and direction of the main airflow and the auxiliary airflow can be controlled online to dynamically optimize the gas-liquid ratio and flow pattern of each annular zone.

[0014] A collaborative control system for a bromine extraction tower system is characterized by comprising: an operating parameter detection unit distributed in each annular reaction zone; wind speed probes distributed in a certain manner to determine the wind speed in each local area; and then a computer to fit the gas distribution of the entire cross section. A central controller electrically connected to each liquid control valve and gas flow regulating device; The built-in control logic module, based on the feedback signal from the operating parameter detection unit, adjusts the liquid spray density and auxiliary air intake of each ring zone in a coordinated manner to achieve active correction of uneven flow field within the tower.

[0015] As a preferred technical solution of the present invention, the control logic module adaptively adjusts the control strategy based on historical operating data and current operating conditions.

[0016] An air-blowing bromine extraction process for a radially partitioned counter-current air-blowing bromine extraction tower system, characterized by comprising the following steps: Step a: Distribute the acidified bromine-containing solution to each ring reaction zone according to a preset ratio using a multi-ring independent liquid distributor; Step b: The main airflow enters the tower from the main air inlet at the center of the tower bottom, and the auxiliary airflow is injected from one or more auxiliary air inlets on the side wall. The airflow direction is adjusted to form a counter-current or cross-flow with the liquid flow. Step c: The gas and liquid phases come into countercurrent contact in the packing layer of each annular region to complete the blowing out of free bromine; Step d: Monitor the operating status of each annular zone in real time, dynamically adjust the liquid distribution ratio and auxiliary air intake parameters, suppress central channel flow and wall flow, and maintain efficient mass transfer throughout the tower.

[0017] As a preferred technical solution of the present invention, in step b, the auxiliary intake air is preferentially injected into the middle ring or outer ring area, and the airflow direction is set to tangential or oblique upward to enhance the gas-liquid disturbance in the edge area.

[0018] As a preferred technical solution of the present invention, the system is controlled by radial partitioning and multidimensional flow field coordination.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention is conducive to improving mass transfer efficiency and bromine recovery level. The concentric annular baffle is used to force the space inside the tower to be divided into zones, which effectively suppresses the gas channeling in the central area and the liquid deviation near the tower wall, so that the packing layer can achieve uniform wetting and full ventilation. Combined with the multi-ring independent liquid distribution and the main and auxiliary synergistic gas intake strategy, the gas-liquid ratio and contact intensity of each area are precisely controlled, thereby greatly improving the bromine blowing efficiency and resource recovery rate.

[0020] 2. This invention overcomes the scale-up limitations of large-diameter towers. Addressing the bottleneck of significantly reduced mass transfer performance in traditional tower equipment as diameter increases, this invention decomposes large-scale complex flow problems into multiple controllable small unit operations by rationally setting the number of zones according to tower diameter. This successfully achieves efficient and stable engineering scale-up, providing reliable core equipment support for ultra-large bromine extraction units. It enables refined and dynamic operation control; the liquid flow rate and auxiliary gas intake of each annulus can be independently adjusted, supporting differentiated operation by region. Combined with an intelligent collaborative control system, it can dynamically optimize the flow field distribution based on real-time operating parameters such as pressure difference and temperature, effectively coping with complex operating conditions such as feed fluctuations and environmental changes, significantly enhancing system operational flexibility and avoiding unplanned downtime caused by localized flooding or dry zones.

[0021] 3. This invention reduces energy consumption and overall operating costs by improving mass transfer efficiency. While achieving the same recovery target, it requires less air, resulting in a corresponding decrease in fan energy consumption. Simultaneously, the packing material is utilized more fully, and the tower height and packing quantity can be optimized appropriately, significantly improving overall system energy efficiency and effectively reducing operating costs. The concentric annular baffle is a fixed internal component with no moving parts, offering advantages such as simple structure, strong corrosion resistance, and long service life. Liquid and gas pipelines are arranged independently in zones, facilitating installation and construction, as well as daily maintenance and zone cleaning, making it flexible for both new construction and upgrades of existing facilities.

[0022] 4. This invention supports the synergistic optimization design of packing and flow field. The zoned structure creates the implementation conditions for configuring differentiated packing in different regions, so that the liquid-gas distribution characteristics and packing performance are matched according to the zone, further releasing the mass transfer potential and promoting the integrated synergistic optimization of structure, materials and flow field.

[0023] 5. This invention has good versatility and potential for technological extension. Although the typical application scenario is air blowing for bromine extraction, the radial partitioning and multi-dimensional control principle it adopts has universality and can be extended to other large-diameter gas-liquid countercurrent packed tower processes, such as flue gas desulfurization, carbon dioxide capture, ammonia recovery, and volatile organic compound removal. It provides an innovative technical path for the design of large towers in the fields of chemical industry, environmental protection and resource recycling. Attached Figure Description

[0024] Figure 1 A data block diagram of the inventive technical features provided for this invention; Figure 2 A data block diagram of the control parameters provided by the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention.

[0026] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] Example 1: A radially partitioned countercurrent air-blowing bromine extraction tower system includes a tower body, a packing layer, a liquid inlet, a gas inlet, and a liquid distributor. The system integrates the following three inseparable structural features: (a) at least one vertically arranged concentric annular baffle that physically divides the cross-section of the tower body into two or more concentric annular reaction zones. The baffle extends from the top of the tower to above the bottom of the packing layer, forcing the gas and liquid phases to flow independently in each annular zone. (b) A multi-ring independent liquid distributor, which includes independent liquid inlet branches corresponding to each annular reaction zone, each branch being equipped with an independently adjustable flow control valve and a distribution nozzle for classifying and adjusting the spray density of each annular zone. (c) A main-auxiliary coordinated gas distribution system, including a main gas inlet located at the center of the bottom of the tower and at least one auxiliary gas inlet located on the side wall of the tower body corresponding to a certain annular reaction zone. The airflow direction of the auxiliary gas inlet is adjustable and can inject gas in a tangential, oblique or radial manner to form a three-dimensional optimized flow field in coordination with the liquid distribution.

[0028] The number of concentric annular baffles is 1 to 3, dividing the tower body into 2 to 4 annular reaction zones.

[0029] The packing material in each annular reaction zone has the same specific surface area, or the specific surface area increases appropriately from the inner ring to the outer ring to form a gradient packing configuration to match the mass transfer requirements of different zones.

[0030] The number of auxiliary air inlets is not less than the number of annular reaction zones minus one, and at least one auxiliary air inlet is located on the sidewall of the outermost annular zone to actively disturb the liquid film on the wall and suppress wall flow.

[0031] Both the main air inlet and the auxiliary air inlet are connected to independent gas flow regulation devices, which allows the flow ratio and direction of the main airflow and the auxiliary airflow to be controlled online, so as to dynamically optimize the gas-liquid ratio and flow pattern of each annular zone.

[0032] A collaborative control system for a bromine extraction tower system is characterized by comprising: operating parameter detection units distributed in each annular reaction zone for real-time acquisition of differential pressure, temperature, and liquid level; A central controller electrically connected to each liquid control valve and gas flow regulating device; The built-in control logic module, based on the feedback signal from the operating parameter detection unit, adjusts the liquid spray density and auxiliary air intake of each ring zone in a coordinated manner to achieve active correction of uneven flow field within the tower.

[0033] The control logic module uses fuzzy control, PID control, or machine learning algorithms to adaptively adjust the control strategy based on historical operating data and current operating conditions.

[0034] An air-blowing bromine extraction process for a radially partitioned counter-current air-blowing bromine extraction tower system includes the following steps: Step a: Distribute the acidified bromine-containing solution to each ring reaction zone according to a preset ratio using a multi-ring independent liquid distributor; Step b: The main airflow enters the tower from the main air inlet at the center of the tower bottom, and the auxiliary airflow is injected from one or more auxiliary air inlets on the side wall. The airflow direction is adjusted to form a counter-current or cross-flow with the liquid flow. Step c: The gas and liquid phases come into countercurrent contact in the packing layer of each annular region to complete the blowing out of free bromine; Step d: Monitor the operating status of each annular zone in real time, dynamically adjust the liquid distribution ratio and auxiliary air intake parameters, suppress central channel flow and wall flow, and maintain efficient mass transfer throughout the tower.

[0035] In step b, auxiliary intake air is preferentially injected into the middle or outer ring region, and the airflow direction is set tangentially or obliquely upward to enhance gas-liquid disturbance in the edge region. The system is controlled in coordination with radial partitioning and multidimensional flow field.

[0036] The working process of the radially partitioned counter-current air-blowing bromine extraction tower system of this invention is based on a specific structure, and achieves efficient, stable, and scalable bromine blowing operation through partitioned supply, coordinated flow, and intelligent control of the gas-liquid two-phase system. Its complete working process is as follows: Step 1: System Start-up and Initial Liquid Distribution Preparation of acidified brine: Bromine-containing brine, such as seawater, is pretreated and then acidified and oxidized by adding sulfuric acid and chlorine gas to oxidize the brine, causing the bromine to...- It is converted into free Br2 to form the liquid to be treated.

[0037] Liquid distribution startup: The feed liquid is delivered to the top of the column by the circulating pump and enters the multi-ring independent liquid distributor. According to preset process parameters, such as column diameter, load, and historical data, the control system sets the opening of the regulating valves in each ring zone, distributing the feed liquid proportionally to the inner ring, middle ring, outer ring, and other annular reaction zones. Packing wetting: The liquid is evenly sprayed through the distribution nozzles and flows downward along the surface of the packing in each ring zone, forming a continuous liquid film and completing the initial wetting.

[0038] Step 2: Gas introduction and countercurrent mass transfer: Main airflow introduction: Compressed air enters from the main air inlet at the center of the bottom of the tower, passes through the packing layer from bottom to top, and forms countercurrent contact with the downstream liquid in each annular zone.

[0039] Auxiliary airflow intervention: At the same time, some air is diverted to the auxiliary air inlet on the side wall via a bypass; the auxiliary air inlet direction is adjusted by the actuator to be tangential or obliquely upward to disturb the liquid film on the outer wall and prevent it from sticking to the tower wall to form ineffective wall flow; additional airflow is injected into the middle / outer ring area to compensate for the insufficient edge air velocity caused by the increase in tower diameter.

[0040] Mass transfer reaction occurs: On the surface of the packing in each annular zone, the rising gas flow continuously blows out the free Br2 in the liquid phase. The Br2 migrates upward with the gas phase and eventually accumulates in the gas at the top outlet of the column. During this stage, due to the presence of physical partitions, the gas-liquid flow in each annular zone is isolated from each other, avoiding the vicious cycle of gas grabbing in the center and liquid accumulation at the edges in traditional columns.

[0041] Step 3, Product Separation and Recycling: Bromine-Rich Gas Discharge: Air carrying Br2 is discharged from the top outlet of the tower and enters the subsequent absorption system, such as the sulfur dioxide absorption tower, to generate hydrobromic acid or further distill to obtain the finished bromine product.

[0042] Mother liquor collection and reuse: The liquid blown out is collected in the liquid collector at the bottom of the tower, and part of it is discharged as waste liquid.

[0043] Step 4: Online monitoring and dynamic control: Real-time parameter acquisition: Differential pressure sensors are installed in each ring zone to monitor gas resistance distribution, temperature sensors to reflect reaction heat and mass transfer intensity, or liquid level / conductivity probes to indirectly determine the liquid film state; data is transmitted to the central controller in real time.

[0044] Intelligent feedback adjustment: If the outer ring pressure difference is detected to be too low, it indicates insufficient airflow or excessively thick liquid film. The system will automatically: increase the opening of the outer ring auxiliary air inlet to increase the local air velocity; and fine-tune the outer ring liquid regulating valve to optimize the spray density.

[0045] Continuous optimization: The control system continuously fine-tunes the liquid-gas parameters of each zone based on preset algorithms, such as PID or adaptive models, to ensure that the entire tower always operates in the high mass transfer efficiency range.

[0046] Step 5: Responding to Operating Condition Fluctuations and Downtime Load change response: When the feed concentration or flow rate changes abruptly, the system can quickly redistribute the liquid volume and auxiliary gas volume in each annulus zone to maintain flow field stability and avoid local flooding or dry blowing.

[0047] Shutdown and cleaning: When shutting down, first cut off the gas supply, then stop the liquid supply; if necessary, backflushing can be carried out in each ring area through independent pipelines to remove packing blockage.

[0048] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A radially partitioned counter-current air-blowing bromine extraction tower system, comprising a tower body, a packing layer, a liquid inlet, a gas inlet, and a liquid distributor, characterized in that, The system integrates the following three inseparable structural features: (a) At least one vertically arranged concentric annular baffle physically divides the cross-section of the tower body into two or more concentric annular reaction zones, the baffle extending from the top of the tower to above the bottom of the packing layer, forcing the gas and liquid phases to flow independently in each annular zone; (b) A multi-ring independent liquid distributor, which includes independent liquid inlet branches corresponding to each annular reaction zone, each branch being equipped with an independently adjustable flow control valve and a distribution nozzle for classifying and adjusting the spray density of each annular zone. (c) A main-auxiliary coordinated gas distribution system, including a main gas inlet located at the center of the bottom of the tower, and at least one auxiliary gas inlet located on the side wall of the tower body corresponding to a certain annular reaction zone. The airflow direction of the auxiliary gas inlet is adjustable, and gas can be injected in a tangential, oblique or radial manner to form a three-dimensional optimized flow field in coordination with the liquid distribution.

2. The radially partitioned counter-current air blowing bromine extraction tower system according to claim 1, characterized in that, The number of concentric annular baffles is 1 to 3, dividing the tower body into 2 to 4 annular reaction zones.

3. The radially partitioned counter-current air blowing bromine extraction tower system according to claim 1 or 2, characterized in that, The packing material in each annular reaction zone has the same specific surface area, or the specific surface area increases appropriately from the inner ring to the outer ring to form a gradient packing configuration to match the mass transfer requirements of different zones.

4. The radially partitioned counter-current air blowing bromine extraction tower system according to claim 1, characterized in that, The number of auxiliary air inlets is not less than the number of annular reaction zones minus one, and at least one auxiliary air inlet is located on the sidewall of the outermost annular zone to actively disturb the liquid film on the wall and suppress wall flow.

5. The radially partitioned counter-current air blowing bromine extraction tower system according to claim 1, characterized in that, Both the main air inlet and the auxiliary air inlet are connected to independent gas flow regulation devices, which allow the flow ratio and direction of the main airflow and the auxiliary airflow to be adjusted online to dynamically optimize the gas-liquid ratio and flow pattern of each annular zone.

6. A collaborative control system for a bromine extraction tower system according to any one of claims 1–5, characterized in that, include: Operating parameter detection units distributed in each annular reaction zone are used to collect parameters characterizing the operating status of each annular zone in real time, including differential pressure, temperature, and liquid level; a central controller; and a built-in control logic module that, based on the feedback signals from the operating parameter detection units, adjusts the liquid spray density and auxiliary air intake of each annular zone in a coordinated manner to achieve active correction of uneven flow field within the tower.

7. The collaborative control system according to claim 6, characterized in that, The control logic module adaptively adjusts the control strategy based on historical operating data and current operating conditions.

8. An air blowing bromine extraction process for a radially partitioned counter-current air blowing bromine extraction tower system according to claim 1, characterized in that, Includes the following steps: Step a: Distribute the acidified bromine-containing solution to each ring reaction zone according to a preset ratio using a multi-ring independent liquid distributor; Step b: The main airflow enters the tower from the main air inlet at the center of the tower bottom, and the auxiliary airflow is injected from one or more auxiliary air inlets on the side wall. The airflow direction is adjusted to form a counter-current or cross-flow with the liquid flow. Step c: The gas and liquid phases come into countercurrent contact in the packing layer of each annular region to complete the blowing out of free bromine; Step d: Monitor the operating status of each annular zone in real time, dynamically adjust the liquid distribution ratio and auxiliary air intake parameters, suppress central channel flow and wall flow, and maintain efficient mass transfer throughout the tower.

9. The air blowing bromine extraction process of the radially partitioned counter-current air blowing bromine extraction tower system according to claim 8, characterized in that, In step b, the auxiliary intake air is preferentially injected into the middle or outer ring area, and the airflow direction is set to tangential or oblique upward to enhance the gas-liquid disturbance in the edge area.

10. The application of the radially partitioned counter-current air blowing bromine extraction tower system according to claim 1 in the extraction of bromine from salt lake brine, seawater, or underground brine, characterized in that, The system is controlled through radial partitioning and multidimensional flow field coordination.

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